* [PATCH] m68k: Avoid VLA use in mangle_kernel_stack()
@ 2019-01-07 9:29 Geert Uytterhoeven
2019-01-08 13:36 ` Arnd Bergmann
2019-01-21 9:41 ` Geert Uytterhoeven
0 siblings, 2 replies; 3+ messages in thread
From: Geert Uytterhoeven @ 2019-01-07 9:29 UTC (permalink / raw)
To: linux-m68k; +Cc: Arnd Bergmann, linux-kernel, Geert Uytterhoeven
With gcc 7.3.0:
arch/m68k/kernel/signal.c: In function ‘mangle_kernel_stack’:
arch/m68k/kernel/signal.c:654:3: warning: ISO C90 forbids variable length array ‘buf’ [-Wvla]
unsigned long buf[fsize / 2]; /* yes, twice as much */
^~~~~~~~
Replace the variable size by the upper limit, which is 168 bytes.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
---
arch/m68k/kernel/signal.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/m68k/kernel/signal.c b/arch/m68k/kernel/signal.c
index e2a9421c57975034..87e7f3639839f559 100644
--- a/arch/m68k/kernel/signal.c
+++ b/arch/m68k/kernel/signal.c
@@ -651,7 +651,8 @@ static int mangle_kernel_stack(struct pt_regs *regs, int formatvec,
regs->vector = formatvec & 0xfff;
} else {
struct switch_stack *sw = (struct switch_stack *)regs - 1;
- unsigned long buf[fsize / 2]; /* yes, twice as much */
+ /* yes, twice as much as max(sizeof(frame.un.fmt<x>)) */
+ unsigned long buf[sizeof(((struct frame *)0)->un) / 2];
/* that'll make sure that expansion won't crap over data */
if (copy_from_user(buf + fsize / 4, fp, fsize))
--
2.17.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] m68k: Avoid VLA use in mangle_kernel_stack()
2019-01-07 9:29 [PATCH] m68k: Avoid VLA use in mangle_kernel_stack() Geert Uytterhoeven
@ 2019-01-08 13:36 ` Arnd Bergmann
2019-01-21 9:41 ` Geert Uytterhoeven
1 sibling, 0 replies; 3+ messages in thread
From: Arnd Bergmann @ 2019-01-08 13:36 UTC (permalink / raw)
To: Geert Uytterhoeven; +Cc: linux-m68k, Linux Kernel Mailing List
On Mon, Jan 7, 2019 at 10:29 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
>
> With gcc 7.3.0:
>
> arch/m68k/kernel/signal.c: In function ‘mangle_kernel_stack’:
> arch/m68k/kernel/signal.c:654:3: warning: ISO C90 forbids variable length array ‘buf’ [-Wvla]
> unsigned long buf[fsize / 2]; /* yes, twice as much */
> ^~~~~~~~
>
> Replace the variable size by the upper limit, which is 168 bytes.
>
> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Arnd Bergmann <arnd@arndb.de>
I also have a couple of build warning fixes for m68k that I might
post in the next few days, for stuff that I ran into while testing my
y2038 series.
Arnd
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] m68k: Avoid VLA use in mangle_kernel_stack()
2019-01-07 9:29 [PATCH] m68k: Avoid VLA use in mangle_kernel_stack() Geert Uytterhoeven
2019-01-08 13:36 ` Arnd Bergmann
@ 2019-01-21 9:41 ` Geert Uytterhoeven
1 sibling, 0 replies; 3+ messages in thread
From: Geert Uytterhoeven @ 2019-01-21 9:41 UTC (permalink / raw)
To: linux-m68k; +Cc: Arnd Bergmann, Linux Kernel Mailing List
On Mon, Jan 7, 2019 at 10:29 AM Geert Uytterhoeven <geert@linux-m68k.org> wrote:
> With gcc 7.3.0:
>
> arch/m68k/kernel/signal.c: In function ‘mangle_kernel_stack’:
> arch/m68k/kernel/signal.c:654:3: warning: ISO C90 forbids variable length array ‘buf’ [-Wvla]
> unsigned long buf[fsize / 2]; /* yes, twice as much */
> ^~~~~~~~
>
> Replace the variable size by the upper limit, which is 168 bytes.
>
> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Thanks, applied and queued for v5.1.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
^ permalink raw reply [flat|nested] 3+ messages in thread
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2019-01-07 9:29 [PATCH] m68k: Avoid VLA use in mangle_kernel_stack() Geert Uytterhoeven
2019-01-08 13:36 ` Arnd Bergmann
2019-01-21 9:41 ` Geert Uytterhoeven
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